Truck has assumed an increasing role in the transportation of goods in societies with a network of roads. The system and method of loading and unloading goods or cargoes on trucks have been improved to increase flexibility and efficiency. The truck bed for holding cargo is usually flat, and came to be known as the flatbed. The cargo that used to be individually wrapped and strapped onto a truck bed is now placed on standardized beds called pallets that are loaded to and from a truck.
Improvements have been made to increase the efficiency of securing loads or pallets onto a truck bed (reference is made to U.S. Pat. Nos. 6,543,990 and 4,642,007). A palletizing system has been disclosed that includes a reusable pallet and a reusable anchoring device for securing cargo. A strap is received and released by a clamping mechanism in a housing on a pallet. A load is placed on a pallet. A strap is put around the load and the pallet. The strap is clamped in a clamping mechanism to secure the load to the pallet. To release the load from the pallet the strap is released from the clamping mechanism.
The load, generally of irregular shape from batch to batch, is typically manually placed onto the pallet till it is in a stable position. A strap has to be adjusted and tightened to the specific shape and size of the load without causing the load to become unstable, a time consuming process. The loading method is manual, varies from load to load, time consuming and often unsuitable for stacking more than a single layer. If only a part of the load needs to be unloaded, the whole load has to be un-strapped first, a portion is to be unloaded, and the remaining load needs to be strapped again, a time consuming and redundant process.
Another method was disclosed for a palletized cylinder distribution system. A raised walkway divides a network that mounts on the rear of a truck. On either side of the walkway the cylinders are placed on pallets that are disposed on the network. Tabs extend laterally from the base of the pallets. The tabs engage a flange defined by the walkway and another flange disposed on side-rails attached to the network, and hold the pallets in place. The bases of the pallets and the surface of the walkway define the bed of the truck. The cylinders are accessed through the walkway.
The loading system and method requires lateral loading of the pallets, and vertical loading of cylinders onto the pallets. It is designed for cylindrical loads and not so flexible to accommodate loads of a general shape and size. The flanges are linear and continuous from pallet to pallet, raising the possibility of damaging pallet to pallet collisions on delicate contents during loading, unloading and transport.
The walkway system constrains pallets by a flange defined by a walkway and another flange defined by a fold-up fence. The flanges are defined by the walkway and fold-up fence, and cannot be quickly reconfigured for different size pallets.
In general, an efficient and reliable loading system should be fast to load and reload cargoes of general shape and size. Further the system and method of loading and unloading cargoes should be repeatable every time, and be compatible with conventionally available material handling equipment (MHE) such as a forklift. The system should not utilize straps for security that tend to entangle in unexpected places and pose an obstacle to a fast and smooth loading and unloading process.
There is still an unsatisfied need for an efficient and reliable cargo loading and unloading system and associated method that are compatible with conventional material handling equipment, to expeditiously deliver critical mission cargo to the field.